Pdcd1

Cell-surface expression of CD4 (BD Biosciences), CD8 (BioLegend), and CD171 (cat#130-100-691, Miltenyi Biotec) was detected by fluorophore-conjugated monoclonal antibodies. EGFRt expression was detected using biotinylated cetuximab (Bristol-Myers Squibb) and a phycoerythrin (PE)-conjugated streptavidin antibody (BioLegend). T cell activation and exhaustion were assessed by fluorophore-conjugated monoclonal antibodies detecting CD137 (BioLegend), CD25 (BioLegend), PD-1 (also known as PDCD1 or CD279, BioLegend), TIM3 (Biolegend), and LAG3 (BD Biosciences). Flow cytometry was performed on a Fortessa X-20 (BD Biosciences) and data were processed using FlowJo software (Tree Star Inc.). Dead cells were excluded from analyses using LIVE/DEAD^TM Fixable Green Dead Cell Stain Kit (Life Technologies).

Cell-surface expression of GD2 (cat#565991, BD Biosciences), CD8 (cat#301041, BioLegend) and CD171 (cat#130–100-691, Miltenyi Biotec) was detected by fluorophore-conjugated monoclonal antibodies. EGFRt expression was detected using biotinylated cetuximab (Bristol-Myers Squibb) and a phycoerythrin (PE)-conjugated streptavidin antibody (cat#12–4317-87, BioLegend). Activation and exhaustion were assessed by fluorophore-conjugated monoclonal antibodies detecting CD137 (cat#309819, BioLegend), CD25 (cat#302622, BioLegend), PD1 (also known as PDCD1 or CD279, cat#329922, BioLegend), TIM3 (cat#345006, Biolegend) and LAG3 (cat#565721, BD Biosciences). Flow cytometry was performed on a Fortessa X-20 (BD Biosciences) and data processed using FlowJo software (Tree Star Inc.). Dead cells were excluded from analyses using LIVE/DEAD™ Fixable Green Dead Cell Stain Kit (cat#L23101, Life Technologies). QuantiBRITE PE calibration beads (BD Biosciences) were used to determine GD2 and CD171 antigen density on retinoblastoma cells according to the manufacturer’s instructions.